diff --git a/src/prolog/indexing.rs b/src/prolog/indexing.rs
index 03208733..fe694d19 100644
--- a/src/prolog/indexing.rs
+++ b/src/prolog/indexing.rs
@@ -74,6 +74,15 @@ impl CodeOffsets {
                 code.push(Self::add_index(is_initial_index, index));
             }
             &Term::Constant(_, ref constant) => {
+                if let Constant::Atom(ref name, _) = constant {
+                    if !name.as_str().is_empty() && name.as_str().chars().skip(1).next().is_none() {
+                        let c = name.as_str().chars().next().unwrap();
+                        let code = self.constants.entry(Constant::Char(c)).or_insert(vec![]);
+                        
+                        code.push(Self::add_index(code.is_empty(), index));
+                    }
+                }
+                
                 let code = self.constants.entry(constant.clone()).or_insert(Vec::new());
 
                 let is_initial_index = code.is_empty();
diff --git a/src/prolog/machine/machine_state_impl.rs b/src/prolog/machine/machine_state_impl.rs
index 10468a36..fec48045 100644
--- a/src/prolog/machine/machine_state_impl.rs
+++ b/src/prolog/machine/machine_state_impl.rs
@@ -1806,7 +1806,7 @@ impl MachineState {
                 let a1 = self.registers[1].clone();
                 let addr = self.store(self.deref(a1));
 
-                let offset = match addr {
+                let offset = match addr {                    
                     Addr::Con(constant) => match hm.get(&constant) {
                         Some(offset) => *offset,
                         _ => 0,