diff --git a/libctru/include/3ds/services/am.h b/libctru/include/3ds/services/am.h
index 4d8b613..50931d2 100644
--- a/libctru/include/3ds/services/am.h
+++ b/libctru/include/3ds/services/am.h
@@ -374,7 +374,7 @@ Result AM_InstallTicketFinish(Handle ticketHandle);
 Result AM_InstallTitleBegin(FS_MediaType mediaType, u64 titleId, bool unk);
 
 /// Stops installing a title, generally to be resumed later.
-Result AM_InstallTitleStop();
+Result AM_InstallTitleStop(void);
 
 /**
  * @brief Resumes installing a title.
@@ -384,10 +384,10 @@ Result AM_InstallTitleStop();
 Result AM_InstallTitleResume(FS_MediaType mediaType, u64 titleId);
 
 /// Aborts installing a title.
-Result AM_InstallTitleAbort();
+Result AM_InstallTitleAbort(void);
 
 /// Finishes installing a title.
-Result AM_InstallTitleFinish();
+Result AM_InstallTitleFinish(void);
 
 /**
  * @brief Commits installed titles.
diff --git a/libctru/include/3ds/services/ps.h b/libctru/include/3ds/services/ps.h
index e138ce5..4ec3a78 100644
--- a/libctru/include/3ds/services/ps.h
+++ b/libctru/include/3ds/services/ps.h
@@ -51,7 +51,7 @@ Result psInitHandle(Handle handle);
 void psExit(void);
 
 /// Returns the PS session handle.
-Handle psGetSessionHandle();
+Handle psGetSessionHandle(void);
 
 /**
  * @brief Signs a RSA signature.
diff --git a/libctru/include/3ds/services/soc.h b/libctru/include/3ds/services/soc.h
index fe49f54..1a71624 100644
--- a/libctru/include/3ds/services/soc.h
+++ b/libctru/include/3ds/services/soc.h
@@ -120,9 +120,9 @@ long gethostid(void);
 // this is supposed to be in unistd.h but newlib only puts it for cygwin, waiting for newlib patch from dkA
 int gethostname(char *name, size_t namelen);
 
-int SOCU_ShutdownSockets();
+int SOCU_ShutdownSockets(void);
 
-int SOCU_CloseSockets();
+int SOCU_CloseSockets(void);
 
 /**
  * @brief Retrieves information from the network configuration. Similar to getsockopt().
diff --git a/libctru/include/3ds/services/uds.h b/libctru/include/3ds/services/uds.h
index ab2e136..a2ecc17 100644
--- a/libctru/include/3ds/services/uds.h
+++ b/libctru/include/3ds/services/uds.h
@@ -323,7 +323,7 @@ Result udsEjectClient(u16 NetworkNodeID);
 /**
  * @brief This can be used by the host to force-disconnect the spectators. Afterwards new spectators will not be allowed to connect until udsAllowSpectators() is used.
  */
-Result udsEjectSpectator();
+Result udsEjectSpectator(void);
 
 /**
  * @brief This can be used by the host to update the network attributes. If bitmask 0x4 is clear in the input bitmask, this clears that bit in the value before actually writing the value into state. Normally you should use the below wrapper functions.
diff --git a/libctru/source/services/am.c b/libctru/source/services/am.c
index 154d727..9fc5cfd 100644
--- a/libctru/source/services/am.c
+++ b/libctru/source/services/am.c
@@ -727,7 +727,7 @@ Result AM_InstallTitleBegin(FS_MediaType mediaType, u64 titleId, bool unk)
 	return (Result)cmdbuf[1];
 }
 
-Result AM_InstallTitleStop()
+Result AM_InstallTitleStop(void)
 {
 	Result ret = 0;
 	u32 *cmdbuf = getThreadCommandBuffer();
@@ -755,7 +755,7 @@ Result AM_InstallTitleResume(FS_MediaType mediaType, u64 titleId)
 }
 
 
-Result AM_InstallTitleAbort()
+Result AM_InstallTitleAbort(void)
 {
 	Result ret = 0;
 	u32 *cmdbuf = getThreadCommandBuffer();
@@ -767,7 +767,7 @@ Result AM_InstallTitleAbort()
 	return (Result)cmdbuf[1];
 }
 
-Result AM_InstallTitleFinish()
+Result AM_InstallTitleFinish(void)
 {
 	Result ret = 0;
 	u32 *cmdbuf = getThreadCommandBuffer();
diff --git a/libctru/source/services/ps.c b/libctru/source/services/ps.c
index 2b029ad..4c7cc61 100644
--- a/libctru/source/services/ps.c
+++ b/libctru/source/services/ps.c
@@ -38,7 +38,7 @@ void psExit(void)
 	psHandle = 0;
 }
 
-Handle psGetSessionHandle()
+Handle psGetSessionHandle(void)
 {
 	return psHandle;
 }
diff --git a/libctru/source/services/soc/soc_closesockets.c b/libctru/source/services/soc/soc_closesockets.c
index 6b5a8aa..27261df 100644
--- a/libctru/source/services/soc/soc_closesockets.c
+++ b/libctru/source/services/soc/soc_closesockets.c
@@ -2,7 +2,7 @@
 #include <3ds/ipc.h>
 #include <3ds/result.h>
 
-int SOCU_CloseSockets()
+int SOCU_CloseSockets(void)
 {
 	u32 *cmdbuf = getThreadCommandBuffer();
 
diff --git a/libctru/source/services/soc/soc_shutdownsockets.c b/libctru/source/services/soc/soc_shutdownsockets.c
index 1649846..8c98caa 100644
--- a/libctru/source/services/soc/soc_shutdownsockets.c
+++ b/libctru/source/services/soc/soc_shutdownsockets.c
@@ -2,7 +2,7 @@
 #include <3ds/ipc.h>
 #include <3ds/result.h>
 
-int SOCU_ShutdownSockets()
+int SOCU_ShutdownSockets(void)
 {
 	u32 *cmdbuf = getThreadCommandBuffer();
 
diff --git a/libctru/source/services/uds.c b/libctru/source/services/uds.c
index 9932169..2611337 100644
--- a/libctru/source/services/uds.c
+++ b/libctru/source/services/uds.c
@@ -335,7 +335,7 @@ Result udsEjectClient(u16 NetworkNodeID)
 	return cmdbuf[1];
 }
 
-Result udsEjectSpectator()
+Result udsEjectSpectator(void)
 {
 	u32* cmdbuf=getThreadCommandBuffer();