diff --git a/main.go b/main.go
index fc9605d..8d5f3e4 100644
--- a/main.go
+++ b/main.go
@@ -26,7 +26,7 @@ func NewConfig()(*Config) {
     for _,v := range os.Environ() {
         splitted := strings.SplitN(v, "=", 2)
         if len(splitted) == 2 {
-            key := strings.TrimSpace(strings.ToLower(splitted[0]))
+            key := strings.TrimSpace(strings.ToUpper(splitted[0]))
             if unicode.IsLetter(getFirstRune(key)) {
                 var entry cEntry
                 entry.value = splitted[1]
@@ -41,7 +41,8 @@ func NewConfig()(*Config) {
 }
 
 func (c *Config) Define(key string, dtype DataType) {
-    entry, ok := c.env[key]
+    upper := strings.ToUpper(key)
+    entry, ok := c.env[upper]
     if ok {
         entry.dtype = dtype
     } else {
@@ -49,12 +50,13 @@ func (c *Config) Define(key string, dtype DataType) {
         entry.dtype = dtype
         entry.unset = true
         entry.empty = true
-        c.env[key] = entry
+        c.env[upper] = entry
     }
 }
 
 func (c *Config) DefineDefault(key string, val string, dtype DataType) {
-    entry, ok := c.env[key]
+    upper := strings.ToUpper(key)
+    entry, ok := c.env[upper]
     if ok {
         if entry.unset {
             entry.empty = false
@@ -66,7 +68,7 @@ func (c *Config) DefineDefault(key string, val string, dtype DataType) {
         entry.dtype = dtype
         entry.unset = true
         entry.empty = false
-        c.env[key] = entry
+        c.env[upper] = entry
     }
 }
 
@@ -101,7 +103,8 @@ func (c *Config) Status()(ok bool) {
 
 func (c *Config) GetInt(key string)(int64) {
     if c.parsed {
-        entry, ok := c.env[key]
+        upper := strings.ToUpper(key)
+        entry, ok := c.env[upper]
         if ok {
             return entry.parsed.intval
         }
@@ -110,7 +113,8 @@ func (c *Config) GetInt(key string)(int64) {
 }
 func (c *Config) GetString(key string)(string) {
     if c.parsed {
-        entry, ok := c.env[key]
+        upper := strings.ToUpper(key)
+        entry, ok := c.env[upper]
         if ok {
             return entry.parsed.strval
         }
@@ -119,7 +123,8 @@ func (c *Config) GetString(key string)(string) {
 }
 func (c *Config) GetDuration(key string)(time.Duration) {
     if c.parsed {
-        entry, ok := c.env[key]
+        upper := strings.ToUpper(key)
+        entry, ok := c.env[upper]
         if ok {
             return entry.parsed.durval
         }
@@ -128,7 +133,8 @@ func (c *Config) GetDuration(key string)(time.Duration) {
 }
 func (c *Config) GetBool(key string)(bool) {
     if c.parsed {
-        entry, ok := c.env[key]
+        upper := strings.ToUpper(key)
+        entry, ok := c.env[upper]
         if ok {
             return entry.parsed.boolval
         }