diff --git a/dlls/dbghelp/dbghelp.c b/dlls/dbghelp/dbghelp.c
index 03e721f0c91..a8e04c73035 100644
--- a/dlls/dbghelp/dbghelp.c
+++ b/dlls/dbghelp/dbghelp.c
@@ -68,9 +68,22 @@ WINE_DEFAULT_DEBUG_CHANNEL(dbghelp);
 
 unsigned   dbghelp_options = SYMOPT_UNDNAME;
 BOOL       dbghelp_opt_native = FALSE;
+SYSTEM_INFO sysinfo;
 
 static struct process* process_first /* = NULL */;
 
+BOOL WINAPI DllMain(HINSTANCE instance, DWORD reason, LPVOID reserved)
+{
+    switch (reason)
+    {
+    case DLL_PROCESS_ATTACH:
+        GetSystemInfo(&sysinfo);
+        DisableThreadLibraryCalls(instance);
+        break;
+    }
+    return TRUE;
+}
+
 /******************************************************************
  *		process_find_by_handle
  *
diff --git a/dlls/dbghelp/dbghelp_private.h b/dlls/dbghelp/dbghelp_private.h
index d55b018fa7a..8fa9e799c07 100644
--- a/dlls/dbghelp/dbghelp_private.h
+++ b/dlls/dbghelp/dbghelp_private.h
@@ -115,6 +115,7 @@ void*    hash_table_iter_up(struct hash_table_iter* hti) DECLSPEC_HIDDEN;
 
 extern unsigned dbghelp_options DECLSPEC_HIDDEN;
 extern BOOL     dbghelp_opt_native DECLSPEC_HIDDEN;
+extern SYSTEM_INFO sysinfo DECLSPEC_HIDDEN;
 
 enum location_kind {loc_error,          /* reg is the error code */
                     loc_unavailable,    /* location is not available */
diff --git a/dlls/dbghelp/elf_module.c b/dlls/dbghelp/elf_module.c
index 142f2f036af..5a6bef947ac 100644
--- a/dlls/dbghelp/elf_module.c
+++ b/dlls/dbghelp/elf_module.c
@@ -137,7 +137,6 @@ struct elf_module_info
 static const char* elf_map_section(struct image_section_map* ism)
 {
     struct elf_file_map*        fmap = &ism->fmap->u.elf;
-    SYSTEM_INFO sysinfo;
     SIZE_T ofst, size;
     HANDLE mapping;
 
@@ -152,7 +151,6 @@ static const char* elf_map_section(struct image_section_map* ism)
     }
 
     /* align required information on allocation granularity */
-    GetSystemInfo(&sysinfo);
     ofst = fmap->sect[ism->sidx].shdr.sh_offset & ~(sysinfo.dwAllocationGranularity - 1);
     size = fmap->sect[ism->sidx].shdr.sh_offset + fmap->sect[ism->sidx].shdr.sh_size - ofst;
     if (!(mapping = CreateFileMappingW(fmap->handle, NULL, PAGE_READONLY, 0, ofst + size, NULL)))
diff --git a/dlls/dbghelp/macho_module.c b/dlls/dbghelp/macho_module.c
index 725363b316f..f10dc78eec8 100644
--- a/dlls/dbghelp/macho_module.c
+++ b/dlls/dbghelp/macho_module.c
@@ -164,11 +164,9 @@ static void macho_calc_range(const struct macho_file_map* fmap, unsigned long of
                              unsigned long len, unsigned long* out_aligned_offset,
                              unsigned long* out_aligned_end, unsigned long* out_misalign)
 {
-    SYSTEM_INFO sysinfo;
     unsigned long pagemask;
     unsigned long file_offset, misalign;
 
-    GetSystemInfo(&sysinfo);
     pagemask = sysinfo.dwAllocationGranularity - 1;
     file_offset = fmap->arch_offset + offset;
     misalign = file_offset & pagemask;