diff --git a/flang/lib/Optimizer/Builder/CUDAIntrinsicCall.cpp b/flang/lib/Optimizer/Builder/CUDAIntrinsicCall.cpp
index e5b07aa3861a..0403a43a845c 100644
--- a/flang/lib/Optimizer/Builder/CUDAIntrinsicCall.cpp
+++ b/flang/lib/Optimizer/Builder/CUDAIntrinsicCall.cpp
@@ -403,16 +403,6 @@ static constexpr IntrinsicHandler cudaHandlers[]{
          &CI::genCUDASetDefaultStream),
      {{{"stream", asValue}}},
      /*isElemental=*/false},
-    {"cudastreamsynchronize",
-     static_cast<CUDAIntrinsicLibrary::ExtendedGenerator>(
-         &CI::genCUDAStreamSynchronize),
-     {{{"stream", asValue}}},
-     /*isElemental=*/false},
-    {"cudastreamsynchronizenull",
-     static_cast<CUDAIntrinsicLibrary::ElementalGenerator>(
-         &CI::genCUDAStreamSynchronizeNull),
-     {},
-     /*isElemental=*/false},
     {"fence_proxy_async",
      static_cast<CUDAIntrinsicLibrary::SubroutineGenerator>(
          &CI::genFenceProxyAsync),
diff --git a/flang/module/cuda_runtime_api.f90 b/flang/module/cuda_runtime_api.f90
index 437bb53d8b27..7c6968cabc37 100644
--- a/flang/module/cuda_runtime_api.f90
+++ b/flang/module/cuda_runtime_api.f90
@@ -36,14 +36,4 @@ interface cudaforsetdefaultstream
   end function
 end interface
 
-interface cudaStreamSynchronize
-  integer function cudastreamsynchronize(stream)
-    import cuda_stream_kind
-    !DIR$ IGNORE_TKR (K) stream
-    integer(kind=cuda_stream_kind), value :: stream
-  end function
-  integer function cudastreamsynchronizenull()
-  end function
-end interface
-
 end module cuda_runtime_api
diff --git a/flang/test/Lower/CUDA/cuda-default-stream.cuf b/flang/test/Lower/CUDA/cuda-default-stream.cuf
index 5bc78af22e84..b9fe1f794959 100644
--- a/flang/test/Lower/CUDA/cuda-default-stream.cuf
+++ b/flang/test/Lower/CUDA/cuda-default-stream.cuf
@@ -39,14 +39,3 @@ end subroutine
 ! CHECK: %{{.*}} = fir.call @_FortranACUFGetDefaultStream() fastmath<contract> : () -> i64
 ! CHECK: %{{.*}} = fir.call @_FortranACUFGetDefaultStream() fastmath<contract> : () -> i64
 
-subroutine stream_synchronize
-  use cuda_runtime_api
-  integer(kind=cuda_stream_kind) :: strm
-  integer :: istat
-  istat = cudastreamsynchronize(strm)
-  istat = cudastreamsynchronize()
-end subroutine
-
-! CHECK-LABEL: func.func @_QPstream_synchronize()
-! CHECK: %{{.*}} = fir.call @_FortranACUFStreamSynchronize(%{{.*}}) fastmath<contract> : (i64) -> i32
-! CHECK: %{{.*}} = fir.call @_FortranACUFStreamSynchronizeNull() fastmath<contract> : () -> i32