diff --git a/cobc/error.c b/cobc/error.c
index cc1e24ebb..2e7d72898 100644
--- a/cobc/error.c
+++ b/cobc/error.c
@@ -74,7 +74,7 @@ cobc_slashify (const char *src)
 	if (is_test < 0)
 		is_test = !!getenv ("COB_IS_RUNNING_IN_TESTMODE");
 
-	if (is_test){
+	if (0 && is_test){
 		int i;
 		int len = strlen (src);
 		char *dst = cobc_malloc (len+1);
diff --git a/tests/testsuite.src/used_binaries.at b/tests/testsuite.src/used_binaries.at
index 49c0ef157..5786ea884 100644
--- a/tests/testsuite.src/used_binaries.at
+++ b/tests/testsuite.src/used_binaries.at
@@ -279,6 +279,30 @@ AT_CHECK([$GREP 'PARAGRAPH_00_l_4:'    prog.c], [0], ignore, [])
 AT_CHECK([$GREP 'PARAGRAPH_EX_l_7:'    prog.c], [0], ignore, [])
 AT_CHECK([$COBCRUN_DIRECT ./prog], [0], [bluBb END], [])
 
+AT_CAPTURE_FILE([prog.d])
+AT_CHECK([$COBC -I sub/copy prog.cob -ext=cpy -o prog.i -MF prog.d -MT "prog.c prog.h" -MT prog$COB_EXE_EXT -MT prog.$COB_OBJECT_EXT -MT prog.i  -fsyntax-only], [0], [], [])
+AT_CHECK([$GREP 'prog.c prog.h '       prog.d], [0], ignore, [])
+AT_CHECK([$GREP ' prog.i:'             prog.d], [0], ignore, [])
+AT_CHECK([$GREP 'sub/copy/PROC.cpy'    prog.d], [0], ignore, [], [
+  # Previous test "failed" --> no entry with slash available, check backslash for this and following tests
+  AT_CHECK([$GREP ' sub\\copy\\PROC.cpy \\'  prog.d], [0], ignore, [])
+  AT_CHECK([$GREP ' sub\\PROCE.cpy'          prog.d], [0], ignore, [])
+  AT_CHECK([$GREP 'sub\\copy\\PROC.cpy:'     prog.d], [0], ignore, [])
+  AT_CHECK([$GREP 'sub\\PROCE.cpy:'          prog.d], [0], ignore, [])
+], [
+  AT_CHECK([$GREP ' sub/copy/PROC.cpy \\'    prog.d], [0], ignore, [])
+  AT_CHECK([$GREP ' sub/PROCE.cpy'           prog.d], [0], ignore, [])
+  AT_CHECK([$GREP 'sub/copy/PROC.cpy:'       prog.d], [0], ignore, [])
+  AT_CHECK([$GREP 'sub/PROCE.cpy:'           prog.d], [0], ignore, [])
+])
+
+# test again with trailing slash which should not result in different files
+AT_CHECK([$COBC -I sub/copy/ prog.cob -ext=cpy -o prog.i -MF prog.d -MT "prog.c prog.h" -MT prog$COB_EXE_EXT -MT prog.$COB_OBJECT_EXT -MT prog.i  -fsyntax-only], [0], [], [])
+AT_CHECK([$GREP 'sub/copy/PROC.cpy'    prog.d], [0], ignore, [], [
+  # Previous test "failed" --> no entry with slash available, check backslash for this test
+  AT_CHECK([$GREP 'sub\\copy\\PROC.cpy'  prog.d], [0], ignore, [])
+])
+
 AT_CLEANUP
 
 
@@ -372,28 +396,13 @@ AT_DATA([prog.cob], [
            EXIT PROGRAM.
 ])
 
-AT_CHECK([TMPDIR="" TMP="notthere" TEMP="" $COMPILE prog.cob 2> compiler.output], [0], [],
-[],[
-    # On Windows, we get a failure from gcc, so the binary is not created, the stderr is mixed and exit code is 1.
-    AT_CHECK([grep libcob: compiler.output], [0], [libcob: warning: Temporary directory TMP is invalid, adjust TMPDIR!
-])
-  ],
-  [
-    AT_CHECK([cat compiler.output], [0], [libcob: warning: Temporary directory TMP is invalid, adjust TMPDIR!
-])
-    AT_CHECK([$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([TMPDIR="" TMP="notthere" TEMP="" $COMPILE prog.cob], [0], [],
+[libcob: warning: Temporary directory TMP is invalid, adjust TMPDIR!
 ])
-  ],
-  [
-    AT_CHECK([cat compiler.output], [0], [libcob: warning: Temporary directory TEMP is invalid, adjust TMPDIR!
+AT_CHECK([$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!
 ])
-  ])
-
 # TMPDIR is only checked when actually needed which is currently only the case
 # for SORT
 #AT_CHECK([TMPDIR="./prog.cob" $COBCRUN_DIRECT ./prog], [0], [OK],
@@ -1072,16 +1081,15 @@ AT_CHECK([$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])
 
-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])
+# 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_CLEANUP
 
@@ -1091,13 +1099,13 @@ 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 rename  (const char *, const char*);
+COB_EXT_IMPORT void f (char *, long);
 ])
 AT_DATA([prog.cob], [
        IDENTIFICATION   DIVISION.
        PROGRAM-ID.      prog.
        PROCEDURE        DIVISION.
-           CALL "rename" USING "Hello".
+           CALL "f" USING "Hello".
 ])
 
 # dynamic call - program seems correct
@@ -1111,8 +1119,10 @@ AT_DATA([prog2.cob], [
        IDENTIFICATION   DIVISION.
        PROGRAM-ID.      prog.
        DATA DIVISION.
+       WORKING-STORAGE SECTION.
+       01 long USAGE BINARY-C-LONG.
        PROCEDURE        DIVISION.
-           CALL "rename" USING "Hello" "Hello2" RETURNING NOTHING.
+           CALL "f" USING "Hello" BY VALUE long RETURNING NOTHING.
 ])
 
 # note: we likely need to build an import library for some environments
@@ -1143,22 +1153,22 @@ 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([rename.copy], [
+AT_DATA([f.copy], [
        IDENTIFICATION DIVISION.
-       PROGRAM-ID. rename PROTOTYPE.
+       PROGRAM-ID. f PROTOTYPE.
        DATA DIVISION.
        LINKAGE SECTION.
        01  a PIC X(20).
-       01  b PIC X(20).
-       PROCEDURE DIVISION USING a b RETURNING OMITTED.
+       01  b BINARY-C-LONG.
+       PROCEDURE DIVISION USING a BY VALUE b RETURNING OMITTED.
        END PROGRAM rename.
 ])
 
-AT_CHECK([$COMPILE_MODULE -Wno-unfinished --copy "rename.copy" -fstatic-call prog2.cob -o prog2c], [0], [],
+AT_CHECK([$COMPILE_MODULE -Wno-unfinished --copy "f.copy" -fstatic-call prog2.cob -o prog2c], [0], [],
 [prog2.cob:8: warning: unexpected RETURNING item
 ], [
   # Previous test "failed" --> retry with import library
-  AT_CHECK([$COMPILE_MODULE -Wno-unfinished --copy "rename.copy" -fstatic-call -L. -lfilec prog2.cob -o prog2c], [0], ignore, ignore)]
+  AT_CHECK([$COMPILE_MODULE -Wno-unfinished --copy "f.copy" -fstatic-call -L. -lfilec prog2.cob -o prog2c], [0], ignore, ignore)]
 )
 
 AT_CLEANUP