diff --git a/lib/util.c b/lib/util.c
index 37cae809..c2593c39 100644
--- a/lib/util.c
+++ b/lib/util.c
@@ -38,6 +38,7 @@
 #include <string.h>
 #include <errno.h>
 #include <fnmatch.h>
+#include <ctype.h>
 #include <sys/utsname.h>
 
 #include "xbps_api_impl.h"
@@ -96,7 +97,10 @@ xbps_pkg_version(const char *pkg)
 	if ((p = strrchr(pkg, '-')) == NULL)
 		return NULL;
 
-	if (strrchr(p, '_') == NULL)
+	if (!isdigit((unsigned char)p[1]))
+		return NULL;
+
+	if (strchr(p, '_') == NULL)
 		return NULL;
 
 	return p + 1; /* skip first '_' */
@@ -113,6 +117,9 @@ xbps_pkg_revision(const char *pkg)
 	if ((p = strrchr(pkg, '_')) == NULL)
 		return NULL;
 
+	if (!isdigit((unsigned char)p[1]))
+		return NULL;
+
 	return p + 1; /* skip first '_' */
 }
 
@@ -126,7 +133,10 @@ xbps_pkg_name(const char *pkg)
 	if ((p = strrchr(pkg, '-')) == NULL)
 		return NULL;
 
-	if (strrchr(p, '_') == NULL)
+	if (!isdigit((unsigned char)p[1]))
+		return NULL;
+
+	if (strchr(p, '_') == NULL)
 		return NULL;
 
 	len = strlen(pkg) - strlen(p) + 1;
diff --git a/tests/xbps/libxbps/util/main.c b/tests/xbps/libxbps/util/main.c
index 7fa85efc..cc1cb655 100644
--- a/tests/xbps/libxbps/util/main.c
+++ b/tests/xbps/libxbps/util/main.c
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 2012 Juan Romero Pardines.
+ * Copyright (c) 2012-2013 Juan Romero Pardines.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -36,14 +36,22 @@ ATF_TC_HEAD(util_test, tc)
 
 ATF_TC_BODY(util_test, tc)
 {
+	ATF_CHECK_EQ(xbps_pkg_name("font-adobe-a"), NULL);
+	ATF_CHECK_EQ(xbps_pkg_name("font-adobe-1"), NULL);
+	ATF_CHECK_EQ(xbps_pkg_name("font-adobe-100dpi"), NULL);
 	ATF_CHECK_EQ(xbps_pkg_name("font-adobe-100dpi-7.8"), NULL);
+	ATF_CHECK_EQ(xbps_pkg_name("python-e_dbus"), NULL);
 	ATF_CHECK_EQ(xbps_pkg_version("font-adobe-100dpi"), NULL);
 	ATF_CHECK_EQ(xbps_pkg_version("font-adobe-100dpi-7.8"), NULL);
+	ATF_CHECK_EQ(xbps_pkg_version("python-e_dbus"), NULL);
+	ATF_CHECK_EQ(xbps_pkg_version("python-e_dbus-1"), NULL);
 	ATF_REQUIRE_STREQ(xbps_pkg_name("font-adobe-100dpi-7.8_2"), "font-adobe-100dpi");
 	ATF_REQUIRE_STREQ(xbps_pkg_name("systemd-43_1"), "systemd");
 	ATF_REQUIRE_STREQ(xbps_pkg_name("font-adobe-100dpi-1.8_blah"), "font-adobe-100dpi");
+	ATF_REQUIRE_STREQ(xbps_pkg_name("python-e_dbus-1.0_1"), "python-e_dbus");
 	ATF_REQUIRE_STREQ(xbps_pkg_version("font-adobe-100dpi-7.8_2"), "7.8_2");
 	ATF_REQUIRE_STREQ(xbps_pkg_version("font-adobe-100dpi-1.8_blah"), "1.8_blah");
+	ATF_REQUIRE_STREQ(xbps_pkg_version("python-e_dbus-1_1"), "1_1");
 	ATF_REQUIRE_STREQ(xbps_pkg_revision("systemd-43_1_0"), "0");
 	ATF_REQUIRE_STREQ(xbps_pkg_revision("systemd_21-43_0"), "0");
 	ATF_REQUIRE_STREQ(xbps_pkgpattern_name("systemd>=43"), "systemd");