diff --git a/cjpeg.c b/cjpeg.c
index cf0e12d5..c23036d7 100644
--- a/cjpeg.c
+++ b/cjpeg.c
@@ -456,7 +456,7 @@ parse_switches(j_compress_ptr cinfo, int argc, char **argv,
         usage();
       cinfo->data_precision = val;
 
-    } else if (keymatch(arg, "progressive", 3)) {
+    } else if (keymatch(arg, "progressive", 1)) {
       /* Select simple progressive mode. */
 #ifdef C_PROGRESSIVE_SUPPORTED
       simple_progressive = TRUE;
@@ -526,7 +526,7 @@ parse_switches(j_compress_ptr cinfo, int argc, char **argv,
        * default sampling factors.
        */
 
-    } else if (keymatch(arg, "scans", 4)) {
+    } else if (keymatch(arg, "scans", 2)) {
       /* Set scan script. */
 #ifdef C_MULTISCAN_FILES_SUPPORTED
       if (++argn >= argc)       /* advance to next argument */
diff --git a/djpeg.c b/djpeg.c
index fde2b8e4..80d79f02 100644
--- a/djpeg.c
+++ b/djpeg.c
@@ -392,7 +392,7 @@ parse_switches(j_decompress_ptr cinfo, int argc, char **argv,
     } else if (keymatch(arg, "report", 2)) {
       report = TRUE;
 
-    } else if (keymatch(arg, "scale", 2)) {
+    } else if (keymatch(arg, "scale", 1)) {
       /* Scale the output image by a fraction M/N. */
       if (++argn >= argc)       /* advance to next argument */
         usage();
diff --git a/jpegtran.c b/jpegtran.c
index 407cc438..b7d7ebbe 100644
--- a/jpegtran.c
+++ b/jpegtran.c
@@ -183,7 +183,7 @@ parse_switches(j_compress_ptr cinfo, int argc, char **argv,
       exit(EXIT_FAILURE);
 #endif
 
-    } else if (keymatch(arg, "copy", 2)) {
+    } else if (keymatch(arg, "copy", 1)) {
       /* Select which extra markers to copy. */
       if (++argn >= argc)       /* advance to next argument */
         usage();
@@ -320,7 +320,7 @@ parse_switches(j_compress_ptr cinfo, int argc, char **argv,
        * handle. */
       transformoption.perfect = TRUE;
 
-    } else if (keymatch(arg, "progressive", 2)) {
+    } else if (keymatch(arg, "progressive", 1)) {
       /* Select simple progressive mode. */
 #ifdef C_PROGRESSIVE_SUPPORTED
       simple_progressive = TRUE;