diff --git a/cobc/ChangeLog b/cobc/ChangeLog
index 2cb212623..b412aaaed 100644
--- a/cobc/ChangeLog
+++ b/cobc/ChangeLog
@@ -114,6 +114,11 @@
 	* codegen.c: handle profiling code generation under the
 	  cb_flag_prof guard
 
+2024-03-15  Fabrice Le Fessant <fabrice.le_fessant@ocamlpro.com>
+
+	* error.c (print_error_prefix): add cobc_slashify to replace backslashes
+	  by slashes, only if COB_IS_RUNNING_IN_TESTMODE is set.
+
 2024-02-19  Boris Eng <boris.eng@ocamlpro.com>
 
 	* parser.y (screen_value_clause): replaced basic literals by literals
diff --git a/cobc/cobc.c b/cobc/cobc.c
index f44c62f75..7d8402f87 100644
--- a/cobc/cobc.c
+++ b/cobc/cobc.c
@@ -9431,10 +9431,14 @@ main (int argc, char **argv)
 		struct cb_text_list	*l;
 		fprintf (cb_depend_file, "%s: \\\n", cb_depend_target);
 		for (l = cb_depend_list; l; l = l->next) {
-			fprintf (cb_depend_file, " %s%s\n", l->text, l->next ? " \\" : "\n");
+			char *filename = cobc_slashify (l->text);
+			fprintf (cb_depend_file, " %s%s\n", filename, l->next ? " \\" : "\n");
+			cobc_free (filename);
 		}
 		for (l = cb_depend_list; l; l = l->next) {
-			fprintf (cb_depend_file, "%s:\n", l->text);
+			char *filename = cobc_slashify (l->text);
+			fprintf (cb_depend_file, "%s:\n", filename);
+			cobc_free (filename);
 		}
 		fclose (cb_depend_file);
 	}
diff --git a/cobc/cobc.h b/cobc/cobc.h
index 822f7381e..28b1ec68f 100644
--- a/cobc/cobc.h
+++ b/cobc/cobc.h
@@ -669,6 +669,8 @@ DECLNORET extern void		cobc_terminate_exit (const char *, const char *) COB_A_NO
 
 extern void		cobc_set_listing_header_code (void);
 
+extern char *		cobc_slashify (const char *);
+
 /* reserved.c */
 extern struct reserved_word_list	*cobc_user_res_list;
 
diff --git a/cobc/error.c b/cobc/error.c
index 97a57cd96..cc1e24ebb 100644
--- a/cobc/error.c
+++ b/cobc/error.c
@@ -62,11 +62,42 @@ size_t				cb_msg_style;
 
 DECLNORET static void		cobc_too_many_errors (void) COB_A_NORETURN;
 
+static int is_test = -1;
+
+/* Returns a copy of the argument with backslashes replaced by slashes
+in filenames, only if COB_IS_RUNNING_IN_TESTMODE. This mode simplifies
+the test of outputs, as they will be similar on Unix and Windows.
+*/
+char *
+cobc_slashify (const char *src)
+{
+	if (is_test < 0)
+		is_test = !!getenv ("COB_IS_RUNNING_IN_TESTMODE");
+
+	if (is_test){
+		int i;
+		int len = strlen (src);
+		char *dst = cobc_malloc (len+1);
+		for (i=0; i<len; i++){
+			char c = src[i];
+			if ( c == '\\' )
+				dst[i] = '/';
+			else
+				dst[i] = c;
+		}
+		dst[i] = 0;
+		return dst;
+	} else
+		return cobc_strdup (src);
+}
+
 static void
 print_error_prefix (const char *file, int line, const char *prefix)
 {
 	if (file) {
 		char *absfile = NULL ;
+		char *tmpfile = cobc_slashify (file);
+		file = tmpfile;
 		if (cb_diagnostics_absolute_paths
 		 && strcmp (file, COB_DASH) != 0
 		 && file[0] != '/'
@@ -100,6 +131,7 @@ print_error_prefix (const char *file, int line, const char *prefix)
 			fprintf (stderr, "%s:%d: ", file, line);
 		}
 		if (absfile) cobc_free (absfile);
+		cobc_free (tmpfile);
 	}
 	if (prefix) {
 		fprintf (stderr, "%s", prefix);
diff --git a/cobc/pplex.l b/cobc/pplex.l
index 68880bb79..35022c1d1 100644
--- a/cobc/pplex.l
+++ b/cobc/pplex.l
@@ -1299,7 +1299,7 @@ ppopen_get_file (const char *name)
 	ppin = fopen (name, "rb");
 #endif
 	if (!ppin) {
-		cb_error ("%s: %s", name, cb_get_strerror ());
+		cb_error ("%s: %s", cobc_slashify (name), cb_get_strerror ());
 		/* Note: postpone error exit as we need the saved buffers later on */
 		return 0;
 	}
@@ -1728,7 +1728,7 @@ ppcopy (const char *name, const char *lib, struct cb_replace_list *replace_list)
 		/* ensure to have errno from name as specified, not from another file */
 		(void)access (plexbuff1, R_OK);
 		/* pass file error as we have no more places to check */
-		cb_error ("%s: %s", plexbuff1, cb_get_strerror ());
+		cb_error ("%s: %s", cobc_slashify (plexbuff1), cb_get_strerror ());
 	}
 
 	/* On COPY, open error restore old file */
diff --git a/tests/testsuite.src/used_binaries.at b/tests/testsuite.src/used_binaries.at
index 50d8a1867..c9cd03b58 100644
--- a/tests/testsuite.src/used_binaries.at
+++ b/tests/testsuite.src/used_binaries.at
@@ -396,13 +396,28 @@ AT_DATA([prog.cob], [
            EXIT PROGRAM.
 ])
 
-AT_CHECK([TMPDIR="" TMP="notthere" TEMP="" $COMPILE prog.cob], [0], [],
-[libcob: warning: Temporary directory TMP is invalid, adjust TMPDIR!
+AT_CHECK([TMPDIR="" TMP="notthere" TEMP="" $COMPILE prog.cob 2> compiler.output], [0], [],
+[],[
+    # On Windows, we get a failure from gcc, so the binary is not created, the stderr is mixed and exit code is 1.
+    AT_CHECK([grep libcob: compiler.output], [0], [libcob: warning: Temporary directory TMP is invalid, adjust TMPDIR!
 ])
-AT_CHECK([$COBCRUN_DIRECT ./prog], [0], [OK], [])
-AT_CHECK([TMPDIR="" TMP="" TEMP="./prog.cob" $COMPILE prog.cob], [0], [],
-[libcob: warning: Temporary directory TEMP is invalid, adjust TMPDIR!
+  ],
+  [
+    AT_CHECK([cat compiler.output], [0], [libcob: warning: Temporary directory TMP is invalid, adjust TMPDIR!
+])
+    AT_CHECK([$COBCRUN_DIRECT ./prog], [0], [OK], [])
+  ])
+
+AT_CHECK([TMPDIR="" TMP="" TEMP="./prog.cob" $COMPILE prog.cob 2> compiler.output], [0], [],
+[],[
+    AT_CHECK([grep libcob: compiler.output], [0], [libcob: warning: Temporary directory TEMP is invalid, adjust TMPDIR!
 ])
+  ],
+  [
+    AT_CHECK([cat compiler.output], [0], [libcob: warning: Temporary directory TEMP is invalid, adjust TMPDIR!
+])
+  ])
+
 # TMPDIR is only checked when actually needed which is currently only the case
 # for SORT
 #AT_CHECK([TMPDIR="./prog.cob" $COBCRUN_DIRECT ./prog], [0], [OK],
@@ -1081,15 +1096,16 @@ AT_CHECK([$COBC -fdiagnostics-plain-output -fdiagnostics-show-caret -Wno-others
 ]])
 
 AT_CHECK([$COMPILE -fdiagnostics-absolute-paths -Wall prog.cob 2> compiler.output], [1])
+AT_CAPTURE_FILE([compiler.output])
+
+AT_CHECK([echo "$PWD/prog.cob:7: error: CRUD.CPY: No such file or directory" > expected.output])
+AT_CHECK([echo "$PWD/prog.cob:6: warning: numeric value is expected" >> expected.output])
+AT_CHECK([echo "$PWD/prog.cob:14: warning: ignoring redundant ." >> expected.output])
+AT_CAPTURE_FILE([expected.output])
 
-# note: -fdiagnostics-absolute-paths will show the realpath,
-#       so for MSYS/MSVC builds that will be x:\something\prog.cob, not the output of PWD,
-#       but the _return_path function from atlocal may adjust that
-AT_CHECK([cat compiler.output | tr '\\' '/' | $SED "s|$(_return_path "$(pwd)")|DIR|"], [0],
-[DIR/prog.cob:7: error: CRUD.CPY: No such file or directory
-DIR/prog.cob:6: warning: numeric value is expected
-DIR/prog.cob:14: warning: ignoring redundant .
-], [], [echo set: $SED "s|$(_return_path "$(pwd)")|DIR|"])
+AT_CHECK([[cat compiler.output | tr '[:upper:]' '[:lower:]' | tr -d ':/\\' > compiler.output2]])
+AT_CHECK([[cat expected.output | tr '[:upper:]' '[:lower:]' | tr -d ':/\\' > expected.output2]])
+AT_CHECK([diff compiler.output2 expected.output2])
 
 AT_CLEANUP
 
@@ -1099,13 +1115,13 @@ AT_SETUP([check include header file])
 
 AT_DATA([filec.h], [
 /* COB_EXT_IMPORT will be defined by libcob.h up-front */
-COB_EXT_IMPORT void f (char *, long);
+COB_EXT_IMPORT void rename  (const char *, const char*);
 ])
 AT_DATA([prog.cob], [
        IDENTIFICATION   DIVISION.
        PROGRAM-ID.      prog.
        PROCEDURE        DIVISION.
-           CALL "f" USING "Hello".
+           CALL "rename" USING "Hello".
 ])
 
 # dynamic call - program seems correct
@@ -1119,10 +1135,8 @@ AT_DATA([prog2.cob], [
        IDENTIFICATION   DIVISION.
        PROGRAM-ID.      prog.
        DATA DIVISION.
-       WORKING-STORAGE SECTION.
-       01 long USAGE BINARY-C-LONG.
        PROCEDURE        DIVISION.
-           CALL "f" USING "Hello" BY VALUE long RETURNING NOTHING.
+           CALL "rename" USING "Hello" "Hello2" RETURNING NOTHING.
 ])
 
 # note: we likely need to build an import library for some environments
@@ -1153,22 +1167,22 @@ AT_CHECK([$COMPILE_MODULE -I . --include "filec.h" -fstatic-call prog2.cob -o pr
 # * putting RETURNING NOTHING is not supported
 # * putting RETURNING OMITTED is ok, but triggers a warning (see stderr)
 
-AT_DATA([f.copy], [
+AT_DATA([rename.copy], [
        IDENTIFICATION DIVISION.
-       PROGRAM-ID. f PROTOTYPE.
+       PROGRAM-ID. rename PROTOTYPE.
        DATA DIVISION.
        LINKAGE SECTION.
        01  a PIC X(20).
-       01  b BINARY-C-LONG.
-       PROCEDURE DIVISION USING a BY VALUE b RETURNING OMITTED.
-       END PROGRAM f.
+       01  b PIC X(20).
+       PROCEDURE DIVISION USING a b RETURNING OMITTED.
+       END PROGRAM rename.
 ])
 
-AT_CHECK([$COMPILE_MODULE -Wno-unfinished --copy "f.copy" -fstatic-call prog2.cob -o prog2c], [0], [],
+AT_CHECK([$COMPILE_MODULE -Wno-unfinished --copy "rename.copy" -fstatic-call prog2.cob -o prog2c], [0], [],
 [prog2.cob:8: warning: unexpected RETURNING item
 ], [
   # Previous test "failed" --> retry with import library
-  AT_CHECK([$COMPILE_MODULE -Wno-unfinished --copy "f.copy" -fstatic-call -L. -lfilec prog2.cob -o prog2c], [0], ignore, ignore)]
+  AT_CHECK([$COMPILE_MODULE -Wno-unfinished --copy "rename.copy" -fstatic-call -L. -lfilec prog2.cob -o prog2c], [0], ignore, ignore)]
 )
 
 AT_CLEANUP