diff --git a/sc2/src/port.h b/sc2/src/port.h
index fc30297f8..1f110b7fd 100644
--- a/sc2/src/port.h
+++ b/sc2/src/port.h
@@ -518,7 +518,12 @@ typedef unsigned int wint_t;
 	// HAVE_UNC_PATHS is defined to signify that Universal Naming Convention
 	// style paths are to be recognised on this platform.
 #	define HAVE_UNC_PATHS
+	// HAVE_CWD_PER_DRIVE is defined to signify that every drive has its own
+	// current working directory.
+#	define HAVE_CWD_PER_DRIVE
 #endif
+// REJECT_DRIVE_PATH_WITHOUT_SLASH can also be defined, if paths of the form
+// "d:foo/bar" (without a slash after the drive letter) are to be rejected.
 
 #endif  /* _PORT_H */
 
diff --git a/sc2/src/sc2code/libs/file/dirs.c b/sc2/src/sc2code/libs/file/dirs.c
index 1e9b27102..c680c8f5b 100644
--- a/sc2/src/sc2code/libs/file/dirs.c
+++ b/sc2/src/sc2code/libs/file/dirs.c
@@ -685,6 +685,13 @@ expandPathAbsolute (char *dest, size_t destLen, const char *src,
 		// Path is of the form "d:path", without a (back)slash after the
 		// semicolon.
 
+#ifdef REJECT_DRIVE_PATH_WITHOUT_SLASH
+		// We reject paths of the form "d:foo/bar".
+		errno = EINVAL;
+		return NULL;
+#elif defined(HAVE_CWD_PER_DRIVE)
+		// Paths of the form "d:foo/bar" are treated as "foo/bar" relative
+		// to the working directory of d:.
 		letter = tolower(src[0]) - 'a';
 
 		// _getdcwd() should only be called on drives that exist.
@@ -706,6 +713,19 @@ expandPathAbsolute (char *dest, size_t destLen, const char *src,
 		}
 
 		src += 2;
+#else  /* if !defined(HAVE_CWD_PER_DRIVE) */
+		// We treat paths of the form "d:foo/bar" as "d:/foo/bar".
+		if (destLen < 3) {
+			errno = ERANGE;
+			return NULL;
+		}
+		dest[0] = src[0];
+		dest[1] = ':';
+		dest[2] = '/';
+		*skipSrc = 2;
+		dest += 3;
+		return dest;
+#endif  /* HAVE_CWD_PER_DRIVE */
 	}
 	else
 #endif  /* HAVE_DRIVE_LETTERS */