diff --git a/src/ca65/incpath.c b/src/ca65/incpath.c
index 9021f44a6..80db9ed63 100644
--- a/src/ca65/incpath.c
+++ b/src/ca65/incpath.c
@@ -38,7 +38,6 @@
 #if defined(_MSC_VER)
 /* Microsoft compiler */
 #  include <io.h>
-#  define R_OK	4
 #else
 /* Anyone else */
 #  include <unistd.h>
@@ -137,10 +136,10 @@ static char* Find (const char* Path, const char* File)
      	strcpy (PathName + Count, File);
 
      	/* Check if this file exists */
-     	if (access (PathName, R_OK) == 0) {
+     	if (access (PathName, 0) == 0) {
      	    /* The file exists */
      	    return xstrdup (PathName);
-     	}		   
+     	}
 
      	/* Skip a list separator if we have one */
      	if (*P == ';') {
diff --git a/src/cc65/error.c b/src/cc65/error.c
index 6a2ab2aaf..dd2d17c57 100644
--- a/src/cc65/error.c
+++ b/src/cc65/error.c
@@ -101,7 +101,7 @@ static char* ErrMsg [ERR_COUNT-1] = {
     "`\"' or `<' expected",
     "Missing terminator or name too long",
     "Include file `%s' not found",
-    "Open failure on include file `%s'",
+    "Cannot open include file `%s': %s",
     "Invalid #error directive",
     "#error: %s",
     "Unexpected `#endif'",
diff --git a/src/cc65/incpath.c b/src/cc65/incpath.c
index 2776099b8..d0ba1f073 100644
--- a/src/cc65/incpath.c
+++ b/src/cc65/incpath.c
@@ -38,7 +38,6 @@
 #if defined(_MSC_VER)
 /* Microsoft compiler */
 #  include <io.h>
-#  define R_OK	4
 #else
 /* Anyone else */
 #  include <unistd.h>
@@ -138,7 +137,7 @@ static char* Find (const char* Path, const char* File)
 	strcpy (PathName + Count, File);
 
 	/* Check if this file exists */
-	if (access (PathName, R_OK) == 0) {
+	if (access (PathName, 0) == 0) {
 	    /* The file exists */
 	    return xstrdup (PathName);
 	}
diff --git a/src/cc65/input.c b/src/cc65/input.c
index a6845e281..72e157bdb 100644
--- a/src/cc65/input.c
+++ b/src/cc65/input.c
@@ -156,7 +156,7 @@ void OpenIncludeFile (const char* Name, unsigned DirSpec)
     F = fopen (N, "r");
     if (F == 0) {
 	/* Error opening the file */
-	PPError (ERR_INCLUDE_OPEN_FAILURE, N);
+	PPError (ERR_INCLUDE_OPEN_FAILURE, N, strerror (errno));
 	xfree (N);
 	return;
     }