diff --git a/rspirv-linker/src/duplicates.rs b/rspirv-linker/src/duplicates.rs
index 7bb3aa5c96..989e837092 100644
--- a/rspirv-linker/src/duplicates.rs
+++ b/rspirv-linker/src/duplicates.rs
@@ -4,6 +4,18 @@ use rspirv::dr::{Instruction, Module, Operand};
 use rspirv::spirv::{Op, Word};
 use std::collections::{hash_map, HashMap, HashSet};
 
+pub fn remove_duplicate_extensions(module: &mut Module) {
+    let mut set = HashSet::new();
+
+    module.extensions.retain(|inst| {
+        inst.class.opcode != Op::Extension
+            || set.insert(match &inst.operands[0] {
+                Operand::LiteralString(s) => s.clone(),
+                _ => panic!(),
+            })
+    });
+}
+
 pub fn remove_duplicate_capablities(module: &mut Module) {
     let mut set = HashSet::new();
     let mut caps = vec![];
diff --git a/rspirv-linker/src/lib.rs b/rspirv-linker/src/lib.rs
index 951654b313..115fc3406a 100644
--- a/rspirv-linker/src/lib.rs
+++ b/rspirv-linker/src/lib.rs
@@ -107,6 +107,7 @@ pub fn link<T>(inputs: &mut [&mut Module], timer: impl Fn(&'static str) -> T) ->
 
     let remove_duplicates_timer = timer("link_remove_duplicates");
     // remove duplicates (https://github.com/KhronosGroup/SPIRV-Tools/blob/e7866de4b1dc2a7e8672867caeb0bdca49f458d3/source/opt/remove_duplicates_pass.cpp)
+    duplicates::remove_duplicate_extensions(&mut output);
     duplicates::remove_duplicate_capablities(&mut output);
     duplicates::remove_duplicate_ext_inst_imports(&mut output);
     duplicates::remove_duplicate_types(&mut output);