diff --git a/linker.go b/linker.go
index 6f97af278..024b72bbc 100644
--- a/linker.go
+++ b/linker.go
@@ -207,13 +207,19 @@ func flattenPrograms(progs map[string]*ProgramSpec, names []string) {
 // dependencies of each program.
 func flattenInstructions(name string, progs map[string]*ProgramSpec, refs map[*ProgramSpec][]string) asm.Instructions {
 	prog := progs[name]
+	progRefs := refs[prog]
+
+	if len(progRefs) == 0 {
+		// No references, nothing to do.
+		return prog.Instructions
+	}
 
 	insns := make(asm.Instructions, len(prog.Instructions))
 	copy(insns, prog.Instructions)
 
 	// Add all direct references of prog to the list of to be linked programs.
-	pending := make([]string, len(refs[prog]))
-	copy(pending, refs[prog])
+	pending := make([]string, len(progRefs))
+	copy(pending, progRefs)
 
 	// All references for which we've appended instructions.
 	linked := make(map[string]bool)
diff --git a/linker_test.go b/linker_test.go
index 39b01cf65..cbe31d683 100644
--- a/linker_test.go
+++ b/linker_test.go
@@ -159,3 +159,24 @@ func TestSplitSymbols(t *testing.T) {
 	qt.Assert(t, qt.HasLen(m["sym3"], 3))
 	qt.Assert(t, qt.HasLen(m["sym4"], 4))
 }
+
+func TestFlattenInstructionsAllocations(t *testing.T) {
+	name := "entrypoint"
+	instructions := asm.Instructions{
+		asm.LoadImm(asm.R0, 0, asm.DWord),
+		asm.Return(),
+	}
+	prog := &ProgramSpec{
+		Name:         name,
+		Instructions: instructions,
+	}
+	progs := map[string]*ProgramSpec{name: prog}
+	refs := make(map[*ProgramSpec][]string)
+
+	// ensure that flattenInstructions does not allocate memory
+	// if there is no reference for the given program.
+	allocs := testing.AllocsPerRun(5, func() {
+		_ = flattenInstructions(name, progs, refs)
+	})
+	qt.Assert(t, qt.Equals(allocs, float64(0)))
+}