diff --git a/inc/C_Instruction.h b/inc/C_Instruction.h
index b898495..225f017 100644
--- a/inc/C_Instruction.h
+++ b/inc/C_Instruction.h
@@ -259,6 +259,10 @@ public:
     aux |= m_instr[6] << 7;
     aux |= m_instr.range(5,3) << 1;
     aux |= m_instr[2] << 5;
+    
+    if (m_instr[12] == 1) {
+        aux |= 0b1111 << 12;
+    }
 
     return aux;
   }
diff --git a/src/Execute.cpp b/src/Execute.cpp
index 25b4435..b99703e 100644
--- a/src/Execute.cpp
+++ b/src/Execute.cpp
@@ -39,7 +39,7 @@ void Execute::AUIPC(Instruction &inst) {
 }
 
 void Execute::JAL(Instruction &inst, bool c_extension, int m_rd) {
-  int32_t mem_addr = 0;
+  int16_t mem_addr = 0;
   int rd;
   int new_pc, old_pc;