diff --git a/src/pk_compiler.c b/src/pk_compiler.c
index 4d61016..ba054c2 100644
--- a/src/pk_compiler.c
+++ b/src/pk_compiler.c
@@ -773,8 +773,15 @@ static void lexToken(Compiler* compiler) {
         break;
       }
 
-      case '.': // TODO: ".5" should be a valid number.
-        setNextTwoCharToken(compiler, '.', TK_DOT, TK_DOTDOT);
+      case '.':
+        if (matchChar(compiler, '.')) {
+          setNextToken(compiler, TK_DOTDOT); // '..'
+        } else if (utilIsDigit(peekChar(compiler))) {
+          eatChar(compiler);   // Consume the decimal point.
+          eatNumber(compiler); // Consume the rest of the number
+        } else {
+          setNextToken(compiler, TK_DOT);    // '.'
+        }
         return;
 
       case '=':
diff --git a/tests/lang/basics.pk b/tests/lang/basics.pk
index e4b03c1..cb85921 100644
--- a/tests/lang/basics.pk
+++ b/tests/lang/basics.pk
@@ -103,6 +103,9 @@ for i in 0..1000
   x = i; assert((x^=-1) == -i-1)
 end
 
+assert(.5 == 0.5)
+assert(.333 == .333)
+assert(.1 + 1 == 1.1)
 
 # If we got here, that means all test were passed.
 print('All TESTS PASSED')