diff --git a/gcc/testsuite/g++.dg/plugin/location-overflow-test-pr96391.c b/gcc/testsuite/g++.dg/plugin/location-overflow-test-pr96391.c
new file mode 100644
index 00000000000..18169617c0c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/plugin/location-overflow-test-pr96391.c
@@ -0,0 +1,12 @@
+/* { dg-options "-fplugin-arg-location_overflow_plugin-value=0x60000001" } */
+
+/* We use location_overflow_plugin.c, which injects the case that location_t
+   values have exceeded LINE_MAP_MAX_LOCATION_WITH_COLS, and hence no column
+   numbers are available.  */
+
+/* Verify that we're in column-less mode.  */
+extern unknown_type test; /* { dg-error "-:'unknown_type' does not name a type" } */
+
+#define CONST const
+#define VOID void
+typedef CONST VOID *PCVOID;
diff --git a/gcc/testsuite/g++.dg/plugin/plugin.exp b/gcc/testsuite/g++.dg/plugin/plugin.exp
index 80c5355fb5e..5cd4b4bff90 100644
--- a/gcc/testsuite/g++.dg/plugin/plugin.exp
+++ b/gcc/testsuite/g++.dg/plugin/plugin.exp
@@ -72,6 +72,8 @@ set plugin_test_list [list \
 	  ../../gcc.dg/plugin/diagnostic-test-string-literals-2.c \
 	  ../../gcc.dg/plugin/diagnostic-test-string-literals-3.c \
 	  ../../gcc.dg/plugin/diagnostic-test-string-literals-4.c } \
+    { ../../gcc.dg/plugin/location_overflow_plugin.c \
+	  location-overflow-test-pr96391.c } \
     { show_template_tree_color_plugin.c \
     	  show-template-tree-color.C \
     	  show-template-tree-color-labels.C \
diff --git a/libcpp/line-map.c b/libcpp/line-map.c
index 2432cd50d26..cccacf2fe5b 100644
--- a/libcpp/line-map.c
+++ b/libcpp/line-map.c
@@ -1417,7 +1417,8 @@ linemap_compare_locations (line_maps *set,
 
   if (l0 == l1
       && pre_virtual_p
-      && post_virtual_p)
+      && post_virtual_p
+      && l0 <= LINE_MAP_MAX_LOCATION_WITH_COLS)
     {
       /* So pre and post represent two tokens that are present in a
 	 same macro expansion.  Let's see if the token for pre was