diff --git a/rocprim/include/rocprim/config.hpp b/rocprim/include/rocprim/config.hpp
index 7c96b54cc..3b6d2929d 100644
--- a/rocprim/include/rocprim/config.hpp
+++ b/rocprim/include/rocprim/config.hpp
@@ -77,28 +77,42 @@
 #undef ROCPRIM_TARGET_CDNA1
 #undef ROCPRIM_TARGET_CDNA2
 #undef ROCPRIM_TARGET_CDNA3
+#undef ROCPRIM_TARGET_UNKNOWN
 
 // See https://llvm.org/docs/AMDGPUUsage.html#instructions
-#if defined(__gfx940__) || defined(__gfx941__) || defined(__gfx942__)
+#if defined(__gfx940__) || defined(__gfx941__) || defined(__gfx942__) || defined(__gfx9_4_generic__)
     #define ROCPRIM_TARGET_CDNA3 1
 #elif defined(__gfx90a__)
     #define ROCPRIM_TARGET_CDNA2 1
 #elif defined(__gfx908__)
     #define ROCPRIM_TARGET_CDNA1 1
 #elif defined(__gfx900__) || defined(__gfx902__) || defined(__gfx904__) || defined(__gfx906__) \
-    || defined(__gfx90c__)
+    || defined(__gfx90c__) || defined(__gfx9_generic__)
     #define ROCPRIM_TARGET_GCN5 1
-#elif defined(__GFX12__)
+#elif defined(__GFX12__) || defined(__gfx12_generic__)
     #define ROCPRIM_TARGET_RDNA4 1
-#elif defined(__GFX11__)
+#elif defined(__GFX11__) || defined(__gfx11_generic__)
     #define ROCPRIM_TARGET_RDNA3 1
 #elif defined(__gfx1030__) || defined(__gfx1031__) || defined(__gfx1032__) || defined(__gfx1033__) \
-    || defined(__gfx1034__) || defined(__gfx1035__) || defined(__gfx1036__)
+    || defined(__gfx1034__) || defined(__gfx1035__) || defined(__gfx1036__)                        \
+    || defined(__gfx10_3_generic__)
     #define ROCPRIM_TARGET_RDNA2 1
-#elif defined(__gfx1010__) || defined(__gfx1011__) || defined(__gfx1012__) || defined(__gfx1013__)
+#elif defined(__gfx1010__) || defined(__gfx1011__) || defined(__gfx1012__) || defined(__gfx1013__) \
+    || defined(__gfx10_1_generic__)
     #define ROCPRIM_TARGET_RDNA1 1
 #elif defined(__GFX8__)
     #define ROCPRIM_TARGET_GCN3 1
+#elif defined(__HIP_DEVICE_COMPILE__)
+    // Double check the build target for typos otherwise please submit an issue or pull request!
+    #warning "unknown build target"
+    #define ROCPRIM_TARGET_UNKNOWN 1
+#endif
+
+// unknown targets do not support 128-bit atomics.
+#if defined(ROCPRIM_TARGET_UKNOWN)
+    #define ROCPRIM_MAX_ATOMIC_SIZE 8
+#else
+    #define ROCPRIM_MAX_ATOMIC_SIZE 16
 #endif
 
 // DPP is supported only after Volcanic Islands (GFX8+)
diff --git a/rocprim/include/rocprim/device/detail/lookback_scan_state.hpp b/rocprim/include/rocprim/device/detail/lookback_scan_state.hpp
index 0376ec4d1..d49d0015c 100644
--- a/rocprim/include/rocprim/device/detail/lookback_scan_state.hpp
+++ b/rocprim/include/rocprim/device/detail/lookback_scan_state.hpp
@@ -108,11 +108,13 @@ enum class lookback_scan_determinism
     default_determinism = nondeterministic,
 };
 
+constexpr const int MAX_PAYLOAD_SIZE = ROCPRIM_MAX_ATOMIC_SIZE - 1;
+
 // lookback_scan_state object keeps track of prefixes status for
 // a look-back prefix scan. Initially every prefix can be either
 // invalid (padding values) or empty. One thread in a block should
 // later set it to partial, and later to complete.
-template<class T, bool UseSleep = false, bool IsSmall = (sizeof(T) <= 15)>
+template<class T, bool UseSleep = false, bool IsSmall = (sizeof(T) <= MAX_PAYLOAD_SIZE)>
 struct lookback_scan_state;
 
 /// Reduce lanes `0-valid_items` and return the result in lane 0.