diff --git a/semver.sh b/semver.sh
index e5237a4..b43f7d6 100755
--- a/semver.sh
+++ b/semver.sh
@@ -1,18 +1,22 @@
-#!/usr/bin/env sh
+#!/bin/bash
 
-function semverParseInto() {
+semverParseInto() {
     local RE='[^0-9]*\([0-9]*\)[.]\([0-9]*\)[.]\([0-9]*\)\([0-9A-Za-z-]*\)'
     #MAJOR
-    eval $2=`echo $1 | sed -e "s#$RE#\1#"`
+    # shellcheck disable=SC2001
+    eval "$2"="$(echo "$1" | sed -e "s#$RE#\1#")"
     #MINOR
-    eval $3=`echo $1 | sed -e "s#$RE#\2#"`
+    # shellcheck disable=SC2001
+    eval "$3"="$(echo "$1" | sed -e "s#$RE#\2#")"
     #MINOR
-    eval $4=`echo $1 | sed -e "s#$RE#\3#"`
+    # shellcheck disable=SC2001
+    eval "$4"="$(echo "$1" | sed -e "s#$RE#\3#")"
     #SPECIAL
-    eval $5=`echo $1 | sed -e "s#$RE#\4#"`
+    # shellcheck disable=SC2001
+    eval "$5"="$(echo "$1" | sed -e "s#$RE#\4#")"
 }
 
-function semverEQ() {
+semverEQ() {
     local MAJOR_A=0
     local MINOR_A=0
     local PATCH_A=0
@@ -23,18 +27,18 @@ function semverEQ() {
     local PATCH_B=0
     local SPECIAL_B=0
 
-    semverParseInto $1 MAJOR_A MINOR_A PATCH_A SPECIAL_A
-    semverParseInto $2 MAJOR_B MINOR_B PATCH_B SPECIAL_B
+    semverParseInto "$1" MAJOR_A MINOR_A PATCH_A SPECIAL_A
+    semverParseInto "$2" MAJOR_B MINOR_B PATCH_B SPECIAL_B
 
-    if [ $MAJOR_A -ne $MAJOR_B ]; then
+    if [[ "$MAJOR_A" -ne "$MAJOR_B" ]]; then
         return 1
     fi
 
-    if [ $MINOR_A -ne $MINOR_B ]; then
+    if [[ "$MINOR_A" -ne "$MINOR_B" ]]; then
         return 1
     fi
 
-    if [ $PATCH_A -ne $PATCH_B ]; then
+    if [[ "$PATCH_A" -ne "$PATCH_B" ]]; then
         return 1
     fi
 
@@ -47,7 +51,7 @@ function semverEQ() {
 
 }
 
-function semverLT() {
+semverLT() {
     local MAJOR_A=0
     local MINOR_A=0
     local PATCH_A=0
@@ -58,21 +62,33 @@ function semverLT() {
     local PATCH_B=0
     local SPECIAL_B=0
 
-    semverParseInto $1 MAJOR_A MINOR_A PATCH_A SPECIAL_A
-    semverParseInto $2 MAJOR_B MINOR_B PATCH_B SPECIAL_B
+    semverParseInto "$1" MAJOR_A MINOR_A PATCH_A SPECIAL_A
+    semverParseInto "$2" MAJOR_B MINOR_B PATCH_B SPECIAL_B
 
-    if [ $MAJOR_A -lt $MAJOR_B ]; then
+    if [[ "$MAJOR_A" -lt "$MAJOR_B" ]]; then
         return 0
     fi
 
-    if [[ $MAJOR_A -le $MAJOR_B  && $MINOR_A -lt $MINOR_B ]]; then
+    if [[ "$MAJOR_A" -gt "$MAJOR_B" ]]; then
+        return 1
+    fi
+
+    if [[ "$MINOR_A" -lt "$MINOR_B" ]]; then
         return 0
     fi
+
+    if [[ "$MINOR_A" -gt "$MINOR_B" ]]; then
+        return 1
+    fi
     
-    if [[ $MAJOR_A -le $MAJOR_B  && $MINOR_A -le $MINOR_B && $PATCH_A -lt $PATCH_B ]]; then
+    if [[ "$PATCH_A" -lt "$PATCH_B" ]]; then
         return 0
     fi
 
+    if [[ "$PATCH_A" -gt "$PATCH_B" ]]; then
+        return 1
+    fi
+
     if [[ "_$SPECIAL_A"  == "_" ]] && [[ "_$SPECIAL_B"  == "_" ]] ; then
         return 1
     fi
@@ -91,40 +107,40 @@ function semverLT() {
 
 }
 
-function semverGT() {
-    semverEQ $1 $2
-    local EQ=$?
+semverGT() {
+    semverEQ "$1" "$2"
+    local EQ="$?"
 
-    semverLT $1 $2
-    local LT=$?
+    semverLT "$1" "$2"
+    local LT="$?"
 
-    if [ $EQ -ne 0 ] && [ $LT -ne 0 ]; then
+    if [[ "$EQ" -ne 0 ]] && [[ "$LT" -ne 0 ]]; then
         return 0
     else
         return 1
     fi
 }
 
-if [ "___semver.sh" == "___`basename $0`" ]; then
+if [[ "___semver.sh" == "___$(basename "$0")" ]]; then
 
 MAJOR=0
 MINOR=0
 PATCH=0
 SPECIAL=""
 
-semverParseInto $1 MAJOR MINOR PATCH SPECIAL
+semverParseInto "$1" MAJOR MINOR PATCH SPECIAL
 echo "$1 -> M: $MAJOR m:$MINOR p:$PATCH s:$SPECIAL"
 
-semverParseInto $2 MAJOR MINOR PATCH SPECIAL
+semverParseInto "$2" MAJOR MINOR PATCH SPECIAL
 echo "$2 -> M: $MAJOR m:$MINOR p:$PATCH s:$SPECIAL"
 
-semverEQ $1 $2
+semverEQ "$1" "$2"
 echo "$1 == $2 -> $?."
 
-semverLT $1 $2
+semverLT "$1" "$2"
 echo "$1 < $2 -> $?."
 
-semverGT $1 $2
+semverGT "$1" "$2"
 echo "$1 > $2 -> $?."
 
 fi