diff --git a/DOCUMENTATION.md b/DOCUMENTATION.md
index d879fff..b1fc7da 100644
--- a/DOCUMENTATION.md
+++ b/DOCUMENTATION.md
@@ -226,32 +226,6 @@ Currently the following low level operations are permitted:
 
 ### Interrupt management
 
-```C
-void vIRQ_SetVectorX(uint32_t irqn, uint32_t vector, uint32_t flag)
-```
-
-<table>
-  <tr>
-    <td>Description</td>
-    <td colspan="2">Register an ISR to the currently active box, with the ability to specify permissions associated with the IRQn slot</td>
-  <tr>
-    <td rowspan="3">Parameters</td>
-    <td><pre>uint32_t irqn<code></td>
-    <td>IRQn</td>
-  </tr>
-  <tr>
-    <td><pre>uint32_t vector<code></td>
-    <td>Interrupt handler; if 0 the IRQn slot is de-registered for the current
-        box</td>
-  </tr>
-  <tr>
-    <td><pre>uint32_t flag<code></td>
-    <td>Permission flag (currently not implemented)</td>
-  </tr>
-</table>
-
----
-
 ```C
 void vIRQ_SetVector(uint32_t irqn, uint32_t vector)
 ```
@@ -272,12 +246,6 @@ void vIRQ_SetVector(uint32_t irqn, uint32_t vector)
   </tr>
 </table>
 
-**Note:**
-
-1. Currently `vIRQ_SetVectorX` and `vIRQ_SetVector` are mapped to the same function because the argument `flag` is not yet used to determine the permissions associated with the IRQn slot
-
-2. `vIRQ_SetVector` is especially kept for backward compatibility with `NVIC_SetVector`
-
 ---
 
 ```C
diff --git a/uvisor-lib/override.h b/uvisor-lib/override.h
index 44a7ac1..f7653fc 100644
--- a/uvisor-lib/override.h
+++ b/uvisor-lib/override.h
@@ -25,7 +25,6 @@
 
 #include <stdint.h>
 
-extern void vIRQ_SetVectorX(uint32_t irqn, uint32_t vector, uint32_t flag);
 extern void vIRQ_SetVector(uint32_t irqn, uint32_t vector);
 extern uint32_t vIRQ_GetVector(uint32_t irqn);
 extern void vIRQ_EnableIRQ(uint32_t irqn);
diff --git a/uvisor-lib/unsupported.h b/uvisor-lib/unsupported.h
index ae6a24d..577ea8e 100644
--- a/uvisor-lib/unsupported.h
+++ b/uvisor-lib/unsupported.h
@@ -66,7 +66,6 @@ UVISOR_EXTERN const uint32_t __uvisor_mode;
 
 /* uvisor-lib/interrupts.h */
 
-#define vIRQ_SetVectorX(irqn, vector, flag) NVIC_SetVector((IRQn_Type) (irqn), (uint32_t) (vector))
 #define vIRQ_SetVector(irqn, vector)        NVIC_SetVector((IRQn_Type) (irqn), (uint32_t) (vector))
 #define vIRQ_GetVector(irqn)                NVIC_GetVector((IRQn_Type) (irqn))
 #define vIRQ_EnableIRQ(irqn)                NVIC_EnableIRQ((IRQn_Type) (irqn))