diff --git a/programs/goo.lua b/programs/goo.lua
index 4639233..0d87f8e 100644
--- a/programs/goo.lua
+++ b/programs/goo.lua
@@ -1,4 +1,4 @@
-local _VERSION = '0.1.1';
+local _VERSION = '0.1.2';
 
 local args = table.pack(...);
 local command = args[1];
@@ -70,6 +70,14 @@ if not turtle then
   error('goo must be run on a turtle');
 end
 
+local function hasPickaxeEquipped()
+  local left = turtle.getEquippedLeft();
+  local right = turtle.getEquippedRight();
+
+  return (left and string.match(left.name or '', '_pickaxe$') ~= nil)
+    or (right and string.match(right.name or '', '_pickaxe$') ~= nil);
+end
+
 local function turnAround()
   turtle.turnRight();
   turtle.turnRight();
@@ -499,6 +507,10 @@ end
 
 print('goo started. Place the turtle directly below the goo block.');
 
+if not hasPickaxeEquipped() then
+  error('goo requires a turtle with a pickaxe equipped');
+end
+
 ensureStartFuel();
 
 while true do