diff --git a/common/Linux/LnxHostSys.cpp b/common/Linux/LnxHostSys.cpp
index 397cfa24e0..81aa1eed4a 100644
--- a/common/Linux/LnxHostSys.cpp
+++ b/common/Linux/LnxHostSys.cpp
@@ -316,7 +316,7 @@ void* HostSys::MapSharedMemory(void* handle, size_t offset, void* baseaddr, size
 {
 	const uint lnxmode = LinuxProt(mode);
 
-	const int flags = (baseaddr != nullptr) ? (MAP_SHARED | MAP_FIXED) : MAP_SHARED;
+	const int flags = (baseaddr != nullptr) ? (MAP_SHARED | MAP_FIXED_NOREPLACE) : MAP_SHARED;
 	void* ptr = mmap(baseaddr, size, lnxmode, flags, static_cast<int>(reinterpret_cast<intptr_t>(handle)), static_cast<off_t>(offset));
 	if (ptr == MAP_FAILED)
 		return nullptr;
@@ -326,7 +326,7 @@ void* HostSys::MapSharedMemory(void* handle, size_t offset, void* baseaddr, size
 
 void HostSys::UnmapSharedMemory(void* baseaddr, size_t size)
 {
-	if (mmap(baseaddr, size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) == MAP_FAILED)
+	if (munmap(baseaddr, size) != 0)
 		pxFailRel("Failed to unmap shared memory");
 }
 
@@ -370,6 +370,7 @@ u8* SharedMemoryMappingArea::Map(void* file_handle, size_t file_offset, void* ma
 {
 	pxAssert(static_cast<u8*>(map_base) >= m_base_ptr && static_cast<u8*>(map_base) < (m_base_ptr + m_size));
 
+	// MAP_FIXED is okay here, since we've reserved the entire region, and *want* to overwrite the mapping.
 	const uint lnxmode = LinuxProt(mode);
 	void* const ptr = mmap(map_base, map_size, lnxmode, MAP_SHARED | MAP_FIXED,
 		static_cast<int>(reinterpret_cast<intptr_t>(file_handle)), static_cast<off_t>(file_offset));