diff --git a/nvm.sh b/nvm.sh
index 5de1858..9781a1f 100755
--- a/nvm.sh
+++ b/nvm.sh
@@ -333,12 +333,12 @@ nvm_format_version() {
 nvm_num_version_groups() {
   local VERSION
   VERSION="$1"
+  VERSION="${VERSION#v}"
+  VERSION="${VERSION%.}"
   if [ -z "$VERSION" ]; then
     echo "0"
     return
   fi
-  VERSION="${VERSION#v*}"
-  VERSION="${VERSION%\.}"
   local NVM_NUM_DOTS
   NVM_NUM_DOTS=$(echo "$VERSION" | command sed -e 's/[^\.]//g')
   local NVM_NUM_GROUPS
diff --git a/test/fast/Unit tests/nvm_num_version_groups b/test/fast/Unit tests/nvm_num_version_groups
index 893da75..88c240e 100755
--- a/test/fast/Unit tests/nvm_num_version_groups	
+++ b/test/fast/Unit tests/nvm_num_version_groups	
@@ -5,13 +5,17 @@ die () { echo $@ ; exit 1; }
 . ../../../nvm.sh
 
 [ "~$(nvm_num_version_groups)" = "~0" ] || die "no args should give 0"
+[ "~$(nvm_num_version_groups v)" = "~0" ] || die "just "v" should give 0"
+[ "~$(nvm_num_version_groups .)" = "~0" ] || die "just "." should give 0"
 [ "~$(nvm_num_version_groups a)" = "~1" ] || die "one letter should give 1"
 
 [ "~$(nvm_num_version_groups 1)" = "~1" ] || die "1 should give 1"
+[ "~$(nvm_num_version_groups 1.)" = "~1" ] || die "1. should give 1"
 [ "~$(nvm_num_version_groups v1)" = "~1" ] || die "v1 should give 1"
 [ "~$(nvm_num_version_groups v1.)" = "~1" ] || die "v1. should give 1"
 
 [ "~$(nvm_num_version_groups 1.2)" = "~2" ] || die "1.2 should give 2"
+[ "~$(nvm_num_version_groups 1.2.)" = "~2" ] || die "1.2. should give 2"
 [ "~$(nvm_num_version_groups v1.2)" = "~2" ] || die "v1.2 should give 2"
 [ "~$(nvm_num_version_groups v1.2.)" = "~2" ] || die "v1.2. should give 2"