diff --git a/.drone.yml b/.drone.yml
index b835d03..4ef8410 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -5,7 +5,7 @@ name: default
 
 steps:
   - name: ameba
-    image: veelenga/ameba
+    image: veelenga/ameba:latest
     commands:
       - ameba src/
   - name: build
diff --git a/src/hence/emulator.cr b/src/hence/emulator.cr
index 7308981..003797c 100644
--- a/src/hence/emulator.cr
+++ b/src/hence/emulator.cr
@@ -82,6 +82,7 @@ module Hence
       )
       end
 
+      # ameba:disable Metrics/CyclomaticComplexity
       def get_register(index : UInt8) : UInt16
         case index
         when 0x0_u8
@@ -121,6 +122,7 @@ module Hence
         end
       end
 
+      # ameba:disable Metrics/CyclomaticComplexity
       def set_register(index : UInt8, value : UInt16) : UInt16
         case index
         when 0x0_u8
@@ -160,6 +162,7 @@ module Hence
         end
       end
 
+      # ameba:disable Metrics/CyclomaticComplexity
       def alu(op : UInt8) : UInt16
         case op
         when 0x00 # not
diff --git a/src/hence/parser.cr b/src/hence/parser.cr
index 0ad2cb3..dd1d20e 100644
--- a/src/hence/parser.cr
+++ b/src/hence/parser.cr
@@ -4,6 +4,7 @@ module Hence
   module Parser
     extend self
 
+    # ameba:disable Metrics/CyclomaticComplexity
     def parse(source : String) : AST
       s = StringScanner.new(source.gsub(/;.*|@.*|#.*/, nil))
       body = [] of AST::Node