diff --git a/src/app-utils/guile-util.c b/src/app-utils/guile-util.c
index 37e58e416f..6c6e4d448d 100644
--- a/src/app-utils/guile-util.c
+++ b/src/app-utils/guile-util.c
@@ -168,10 +168,11 @@ gnc_guile_call1_to_string(SCM func, SCM arg)
 
             x = scm_to_locale_string(value);
 
-            /* scm_to_locale_string() returns a malloc'ed string.
-               Copy to a g_malloc'ed one. */
+            /* scm_to_locale_string() returns a malloc'ed string in
+               guile-1.8 (but not in guile-1.6).  Copy to a
+               g_malloc'ed one. */
             s = g_strdup(x);
-            free(x);
+            gnc_free_scm_locale_string(x);
             return s;
         }
         else
@@ -675,10 +676,11 @@ gnc_split_scm_get_memo(SCM split_scm)
 
     x = scm_to_locale_string(result);
 
-    /* scm_to_locale_string() returns a malloc'ed string.
+    /* scm_to_locale_string() returns a malloc'ed string in
+       guile-1.8 (but not in guile-1.6).
        Copy to a g_malloc'ed one. */
     s = g_strdup(x);
-    free(x);
+    gnc_free_scm_locale_string(x);
     return s;
 }
 
@@ -708,10 +710,11 @@ gnc_split_scm_get_action(SCM split_scm)
 
     x = scm_to_locale_string(result);
 
-    /* scm_to_locale_string() returns a malloc'ed string.
+    /* scm_to_locale_string() returns a malloc'ed string in
+       guile-1.8 (but not in guile-1.6).
        Copy to a g_malloc'ed one. */
     s = g_strdup(x);
-    free(x);
+    gnc_free_scm_locale_string(x);
     return s;
 }
 
@@ -1146,10 +1149,11 @@ gnc_get_debit_string(GNCAccountType account_type)
 
     x = scm_to_locale_string(result);
 
-    /* scm_to_locale_string() returns a malloc'ed string.
+    /* scm_to_locale_string() returns a malloc'ed string in
+       guile-1.8 (but not in guile-1.6).
        Copy to a g_malloc'ed one. */
     s = g_strdup(x);
-    free(x);
+    gnc_free_scm_locale_string(x);
     return s;
 }
 
@@ -1186,10 +1190,11 @@ gnc_get_credit_string(GNCAccountType account_type)
 
     x = scm_to_locale_string(result);
 
-    /* scm_to_locale_string() returns a malloc'ed string.
+    /* scm_to_locale_string() returns a malloc'ed string in
+       guile-1.8 (but not in guile-1.6).
        Copy to a g_malloc'ed one. */
     s = g_strdup(x);
-    free(x);
+    gnc_free_scm_locale_string(x);
     return s;
 }
 
diff --git a/src/gnome-utils/gnc-menu-extensions.c b/src/gnome-utils/gnc-menu-extensions.c
index a7b586d906..95743f26bd 100644
--- a/src/gnome-utils/gnc-menu-extensions.c
+++ b/src/gnome-utils/gnc-menu-extensions.c
@@ -184,7 +184,7 @@ gnc_extension_path (SCM extension, char **fullpath)
             {
                 strings[i] = g_strdup(gettext(s));
             }
-            free(s);
+            gnc_free_scm_locale_string(s);
         }
         else
         {
diff --git a/src/guile-mappings.h b/src/guile-mappings.h
index 4a5c7bee66..7ae8859b31 100644
--- a/src/guile-mappings.h
+++ b/src/guile-mappings.h
@@ -30,11 +30,22 @@
 # define scm_is_symbol SCM_SYMBOLP
 # define scm_is_true SCM_NFALSEP
 # define scm_is_vector SCM_VECTORP
-# define scm_to_locale_string SCM_STRING_CHARS
 # define scm_c_string_length SCM_STRING_LENGTH
 #elif (SCM_MAJOR_VERSION == 1) && (SCM_MINOR_VERSION <= 8)
 # define scm_c_string_length scm_i_string_length
 #endif
+
+/* The result of SCM_STRING_CHARS must not be free'd, but the result
+ * of scm_to_locale_string must. That's bad. We define the macro
+ * gnc_free_scm_locale_string to wrap around free() for that
+ * reason. */
+#if (SCM_MAJOR_VERSION == 1) && (SCM_MINOR_VERSION <= 6)
+# define scm_to_locale_string SCM_STRING_CHARS
+# define gnc_free_scm_locale_string (void)
+#else
+# define gnc_free_scm_locale_string free
+#endif
+
 /* Convenience macros */
 
 #define scm_is_equal(obj1,obj2)	scm_is_true(scm_equal_p(obj1,obj2))