diff --git a/src/processor.cpp b/src/processor.cpp
index c8412bf037c26..a3502eb9dac99 100644
--- a/src/processor.cpp
+++ b/src/processor.cpp
@@ -630,11 +630,12 @@ static inline jl_image_t parse_sysimg(void *hdl, F &&callback)
     jl_dlsym(hdl, "jl_image_pointers", (void**)&pointers, 1);
 
     const void *ids = pointers->target_data;
-    jl_value_t* rejection_reason = C_NULL;
+    jl_value_t* rejection_reason = nullptr;
     JL_GC_PUSH1(&rejection_reason);
     uint32_t target_idx = callback(ids, &rejection_reason);
-    if target_idx == -1;
-        jl_error(rejection_reason);
+    if (target_idx == (uint32_t)-1) {
+        jl_throw(jl_new_struct(jl_errorexception_type, rejection_reason));
+    }
     JL_GC_POP();
 
     if (pointers->header->version != 1) {
@@ -984,7 +985,7 @@ extern "C" JL_DLLEXPORT jl_value_t* jl_reflect_clone_targets() {
         data.insert(data.end(), specdata.begin(), specdata.end());
     }
 
-    arr = (jl_value_t*)jl_alloc_array_1d(jl_array_uint8_type, data.size());
+    jl_value_t *arr = (jl_value_t*)jl_alloc_array_1d(jl_array_uint8_type, data.size());
     uint8_t *out = (uint8_t*)jl_array_data(arr);
     memcpy(out, data.data(), data.size());
     return arr;
diff --git a/src/processor_arm.cpp b/src/processor_arm.cpp
index 972d4b171b057..22427107bc34e 100644
--- a/src/processor_arm.cpp
+++ b/src/processor_arm.cpp
@@ -1825,7 +1825,7 @@ JL_DLLEXPORT jl_value_t* jl_check_pkgimage_clones(char *data)
     JL_GC_PUSH1(&rejection_reason);
     uint32_t match_idx = pkgimg_init_cb(data, &rejection_reason);
     JL_GC_POP();
-    if (match_idx == -1)
+    if (match_idx == (uint32_t)-1)
         return rejection_reason;
     return jl_nothing;
 }
diff --git a/src/processor_fallback.cpp b/src/processor_fallback.cpp
index a46851eac2983..40137efbfaa5b 100644
--- a/src/processor_fallback.cpp
+++ b/src/processor_fallback.cpp
@@ -176,7 +176,7 @@ JL_DLLEXPORT jl_value_t* jl_check_pkgimage_clones(char *data)
     JL_GC_PUSH1(&rejection_reason);
     uint32_t match_idx = pkgimg_init_cb(data, &rejection_reason);
     JL_GC_POP();
-    if (match_idx == -1)
+    if (match_idx == (uint32_t)-1)
         return rejection_reason;
     return jl_nothing; 
 }
diff --git a/src/processor_x86.cpp b/src/processor_x86.cpp
index de1b383ad196f..d690d7cd60dd2 100644
--- a/src/processor_x86.cpp
+++ b/src/processor_x86.cpp
@@ -869,7 +869,7 @@ static uint32_t sysimg_init_cb(const void *id, jl_value_t** rejection_reason)
                  "https://docs.julialang.org/en/v1/devdocs/sysimg/ for more.");
     }
     auto match = match_sysimg_targets(sysimg, target, max_vector_size, rejection_reason);
-    if match.best_idx == -1
+    if (match.best_idx == (uint32_t)-1)
         return match.best_idx;
     // Now we've decided on which sysimg version to use.
     // Make sure the JIT target is compatible with it and save the JIT target.
@@ -1040,7 +1040,7 @@ JL_DLLEXPORT jl_value_t* jl_check_pkgimage_clones(char *data)
     JL_GC_PUSH1(&rejection_reason);
     uint32_t match_idx = pkgimg_init_cb(data, &rejection_reason);
     JL_GC_POP();
-    if (match_idx == -1)
+    if (match_idx == (uint32_t)-1)
         return rejection_reason;
     return jl_nothing;
 }