diff --git a/src/main/java/dan200/computercraft/core/apis/OSAPI.java b/src/main/java/dan200/computercraft/core/apis/OSAPI.java
index 3432dc7a8..dbf7d6b83 100644
--- a/src/main/java/dan200/computercraft/core/apis/OSAPI.java
+++ b/src/main/java/dan200/computercraft/core/apis/OSAPI.java
@@ -298,7 +298,7 @@ public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull O
             {
                 // time
                 String param = optString( args, 0, "ingame" );
-                switch( param )
+                switch( param.toLowerCase( Locale.ROOT ) )
                 {
                     case "utc":
                     {
@@ -326,7 +326,7 @@ public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull O
             {
                 // day
                 String param = optString( args, 0, "ingame" );
-                switch( param )
+                switch( param.toLowerCase( Locale.ROOT ) )
                 {
                     case "utc":
                     {
@@ -380,7 +380,7 @@ public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull O
             {
                 // epoch
                 String param = optString( args, 0, "ingame" );
-                switch( param )
+                switch( param.toLowerCase( Locale.ROOT ) )
                 {
                     case "utc":
                     {