diff --git a/src/mminou.c b/src/mminou.c
index a36d60e3..e6c8579a 100644
--- a/src/mminou.c
+++ b/src/mminou.c
@@ -501,7 +501,7 @@ void printLongLine(const char *line, const char *startNextLine, const char *brea
   vstring_def(prefix);
   vstring_def(startNextLine1);
   vstring_def(breakMatch1);
-  long i, j, p;
+  long i, p;
   long startNextLineLen;
   flag firstLine;
   flag tildeFlag = 0;
@@ -559,11 +559,6 @@ void printLongLine(const char *line, const char *startNextLine, const char *brea
   // where all ASCII 3's are converted back to space.
   // Note added 20-Oct-02: tidy.exe breaks HREF quotes with new line.
   // Check HTML spec - do we really need this code?
-  j = (long)strlen(multiLine);
-  // Do a bug check to make sure no real ASCII 3's are ever printed
-  for (i = 0; i < j; i++) {
-    if (multiLine[i] == QUOTED_SPACE) bug(1514); // Should never be the case
-  }
   if (breakMatch1[0] == '\"') {
     breakMatch1[0] = ' '; // Change to a space (the real break character)
     // Scan string for quoted strings
diff --git a/src/mmwtex.c b/src/mmwtex.c
index 60d9f34d..96f5063f 100644
--- a/src/mmwtex.c
+++ b/src/mmwtex.c
@@ -59,6 +59,15 @@ pntrString_def(g_mathboxUser); // User name vs. mathbox #
 // in a math string in a comment to be removed for HTML output.
 #define CLOSING_PUNCTUATION ".,;)?!:]'\"_-"
 
+/*!
+ * \def QUOTED_SPACE
+ * The general line wrapping algorithm looks out for spaces as break positions.
+ * To prevent a quote delimited by __"__ be broken down, spaces are temporarily
+ * replaced with 0x03 (ETX, end of transmission), hopefully never used in
+ * text in this application.
+ */
+#define QUOTED_SPACE 3 // ASCII 3 that temporarily zaps a space
+
 // Tex output file
 FILE *g_texFilePtr = NULL;
 flag g_texFileOpenFlag = 0;
@@ -2806,10 +2815,11 @@ void printTexLongMath(nmbrString *mathString,
     long indentationLevel)
 {
 #define INDENTATION_OFFSET 1
-  long i;
+  long i, j, k, n;
   long pos;
   vstring_def(tex);
   vstring_def(texLine);
+  vstring_def(texFull);
   vstring_def(sPrefix);
   vstring_def(htmStep);
   vstring_def(htmStepTag);
@@ -3047,56 +3057,72 @@ void printTexLongMath(nmbrString *mathString,
     if (!g_oldTexFlag) {
       if (refType == 'e' || refType == 'f') {
         // A hypothesis - don't include \ref{}
-        printLongLine(cat("  ",
-            // If not first step, so print "\\" LaTeX line break
-            !strcmp(htmStep, "1") ? "" : "\\\\ ",
-            htmStep, // Step number
-            " && ",
-            " & ",
-            texLine,
-            // Don't put space to help prevent bad line break
-            "&\\text{Hyp~",
-            // The following puts a hypothesis number such as "2" if
-            // $e label is "abc.2"; if no ".", will be whole label.
-            right(htmRef, instr(1, htmRef, ".") + 1),
-            "}\\notag%",
-            // Add full label as LaTeX comment - note lack of space after
-            // "%" above to prevent bad line break.
-            htmRef, NULL),
-            "    \\notag \\\\ && & \\qquad ", // Continuation line prefix
-            " ");
+        texFull = cat("  ", // texFull[0] should not be a "{" character.
+          // If not first step, so print "\\" LaTeX line break
+          !strcmp(htmStep, "1") ? "" : "\\\\ ",
+          htmStep, // Step number
+          " && ",
+          " & ",
+          texLine,
+          // Don't put space to help prevent bad line break
+          "&\\text{Hyp~",
+          // The following puts a hypothesis number such as "2" if
+          // $e label is "abc.2"; if no ".", will be whole label.
+          right(htmRef, instr(1, htmRef, ".") + 1),
+          "}\\notag%",
+          // Add full label as LaTeX comment - note lack of space after
+          // "%" above to prevent bad line break.
+          htmRef, NULL);
       } else {
-        printLongLine(cat("  ",
-            // If not first step, so print "\\" LaTeX line break
-            !strcmp(htmStep, "1") ? "" : "\\\\ ",
-            htmStep, // Step number
-            " && ",
-
-            // Local label if any e.g. "@2:"
-            (htmLocLab[0] != 0) ? cat(htmLocLab, "\\ ", NULL) : "",
-
-            " & ",
-            texLine,
-            // Don't put space to help prevent bad line break
-
-            // Surround \ref with \mbox for non-math-mode
-            // symbolic labels (due to \tag{..} in mmcmds.c).  Also,
-            // move hypotheses to after referenced label.
-            "&",
-            "(",
-
-            // Don't make local label a \ref
-            (htmRef[0] != '@') ?
-                cat("\\mbox{\\ref{eq:", htmRef, "}}", NULL)
-                : htmRef,
-
-            htmHyp[0] ? "," : "",
-            htmHyp,
-            ")\\notag", NULL),
-
-            "    \\notag \\\\ && & \\qquad ", // Continuation line prefix
-            " ");
+        texFull = cat("  ", // texFull[0] should not be a "{" character.
+          // If not first step, so print "\\" LaTeX line break
+          !strcmp(htmStep, "1") ? "" : "\\\\ ",
+          htmStep, // Step number
+          " && ",
+
+          // Local label if any e.g. "@2:"
+          (htmLocLab[0] != 0) ? cat(htmLocLab, "\\ ", NULL) : "",
+
+          " & ",
+          texLine,
+          // Don't put space to help prevent bad line break
+
+          // Surround \ref with \mbox for non-math-mode
+          // symbolic labels (due to \tag{..} in mmcmds.c).  Also,
+          // move hypotheses to after referenced label.
+          "&",
+          "(",
+
+          // Don't make local label a \ref
+          (htmRef[0] != '@') ?
+              cat("\\mbox{\\ref{eq:", htmRef, "}}", NULL)
+              : htmRef,
+
+          htmHyp[0] ? "," : "",
+          htmHyp,
+          ")\\notag", NULL);
+      }
+      // To avoid generating incorrect TeX, line breaking is forbidden inside
+      // scopes of curly braces.  However breaking between '\{' and '\}' is
+      // allowed.
+      // The spaces that should not be matched with 'breakMatch' are
+      // temporarily changed to ASCII 3 before the 'printLongLine' procedure
+      // is called.  The procedure rewraps the 'line' argument matching the
+      // unchanged spaces only, thus ensuring bad breaks will be avoided.
+      // The reverse is done in the 'print2()' function, where all ASCII 3's
+      // are converted back to spaces.
+      // k counts the scope level we are in.
+      k = 0;
+      n = (long)strlen(texFull);
+      for (j = 1; j < n; j++) { // We don't need to check texFull[0].
+        // We enter a non "\{" scope.
+        if (texFull[j] == '{' && texFull[j - 1] != '\\') k++;
+        // We escape a non "\}" scope.
+        if (texFull[j] == '}' && texFull[j - 1] != '\\') k--;
+        // If k > 0 then we are inside a scope.
+        if (texFull[j] == ' ' && k > 0) texFull[j] = QUOTED_SPACE;
       }
+      printLongLine(texFull, "    \\notag \\\\ && & \\qquad ", /* Continuation line prefix */ " ");
     } else {
       printLongLine(texLine, "", "\\");
       print2("\\endm\n");
diff --git a/tests/.gitignore b/tests/.gitignore
index 43f7c2e6..74bcd279 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -1,2 +1,3 @@
+issue129.tex
 issue134.tex
 underscores.html
\ No newline at end of file
diff --git a/tests/issue129.expected b/tests/issue129.expected
new file mode 100644
index 00000000..1e109f83
--- /dev/null
+++ b/tests/issue129.expected
@@ -0,0 +1,44 @@
+MM> READ "issue129.mm"
+Reading source file "issue129.mm"... 121 bytes
+121 bytes were read into the source buffer.
+The source has 3 statements; 1 are $a and 1 are $p.
+No errors were found.  However, proofs were not checked.  Type VERIFY PROOF *
+if you want to check them.
+MM> Continuous scrolling is now in effect.
+MM> Created LaTeX output file "issue129.tex".
+Reading definitions from $t statement of issue129.mm...
+1 typesetting statements were read from "issue129.mm".
+MM> Outputting proof of "th1"...
+The LaTeX source was written to "issue129.tex".
+MM> The LaTeX output file "issue129.tex" has been closed.
+MM> Entering the Text Tools utilities.  Type HELP for help, EXIT to exit.
+TOOLS> The input had 28 lines, the output has 27 lines. First output line:
+\documentclass{article}
+TOOLS> Exiting the Text Tools.  Type EXIT again to exit Metamath.
+MM> \documentclass{article}
+\usepackage{amssymb} % amssymb must be loaded before phonetic
+\usepackage{phonetic} % for \riota
+\usepackage{mathrsfs} % for \mathscr
+\usepackage{mathtools} % loads package amsmath
+\usepackage{amsthm} % amsthm must be loaded after amsmath
+\usepackage{accents} % accents should be loaded after mathtools
+\theoremstyle{plain}
+\newtheorem{theorem}{Theorem}[section]
+\newtheorem{definition}[theorem]{Definition}
+\newtheorem{lemma}[theorem]{Lemma}
+\newtheorem{axiom}{Axiom}
+\allowdisplaybreaks[1] % Allow page breaks in {align}
+\usepackage[plainpages=false,pdfpagelabels]{hyperref}
+\hypersetup{colorlinks} % Get rid of boxes around links
+\begin{document}
+
+\begin{proof}
+\begin{align}
+  1 &&  & \text{ A A A A A A A A A A } \text{ A A A A A A A A A A }
+    \notag \\ && & \qquad \text{ A A A A A A A A A A }
+    \notag \\ && & \qquad \text{ A A A A A A A A A A }
+\text{ A A A A A A A A A A }&(\mbox{\ref{eq:ax-1}})\notag
+\end{align}
+\end{proof}
+
+\end{document}
diff --git a/tests/issue129.in b/tests/issue129.in
new file mode 100644
index 00000000..6078bc29
--- /dev/null
+++ b/tests/issue129.in
@@ -0,0 +1,7 @@
+open tex issue129.tex
+show proof th1 /tex
+close tex
+tools
+match issue129.tex "% This LaTeX file was created by Metamath on " N
+exit
+"cat issue129.tex"
diff --git a/tests/issue129.mm b/tests/issue129.mm
new file mode 100644
index 00000000..5ef3b6d4
--- /dev/null
+++ b/tests/issue129.mm
@@ -0,0 +1,9 @@
+$c A $.
+
+ax-1 $a A A A A A $.
+
+th1 $p A A A A A $= ax-1 $.
+
+$( $t
+    latexdef "A" as "\text{ A A A A A A A A A A }";
+$)
diff --git a/tests/run_test.sh b/tests/run_test.sh
index 052782f1..d9e6afe3 100755
--- a/tests/run_test.sh
+++ b/tests/run_test.sh
@@ -110,7 +110,7 @@ for test in "$@"; do
   # a new version comes out.
   # The last line is always 'MM> EXIT' which is not relevant.
   # The sed is to redact timings, which are nondeterministic
-  echo "$result" | head -n -1 | tail -n +2 \
+  printf "%s" "$result" | head -n -1 | tail -n +2 \
     | sed -e 's/ \+[0-9]\+\.[0-9]\+ s/ x.xx s/g' \
     > "$outfile"